Plugging water sands by a soap precipitate



*May 4, 1937. G. E. CANNON 2,079,431.

PLUGGING WATER SANDS BY A SOAP PRECIPITATE Filed OCb. 17, 1954 FLUID INLET FLv/ 007252' PLI/ID TMR n" MW/ Patented May 4, 1937 2,079,431

UNITED STATES PATENT OFFICE PLUGGING WATER sANps Br A soAr r PRECIPITATE George E. Cannon, Houston, Tex., assignor to Standard Oil Development Company, a corporation of Delaware Application October 17, 1934, Serial No. 748,579 2 Claims. (Cl. 166-21) This invention relates to improvements in exsubstance within the interstices of the sand at cluding water from oil and gas Wells. 20, which plugs the pores of the sand and ren- In producing oil or gas from a well, water freders it impervious to water flow. quently enters thewell along with the oil or gas. The fluid used comprises a solution of soap 5 Production of water in this manner is undesirable which reacts with the salts dissolved in the wa- 5 and frequently attempts are made to shut off the ter to form a precipitate in the pores of the waflow of water by cementing the lower portion of ter-bearing sand. The solution of soap may the well or by driving lead wool into the bottom comprise water soluble salts of fatty raw mavof the well. In shutting off water by the methterial furnished by any oil or fat of vegetable lo ods commonly in use, it frequently happens that or animal origin. Preferably the soap is a wam a portion of the oil-bearing stratum is plugged ter-soluble soap such as soaps of the alkali metals ofi also and the oil containedin such stratum is or ammonium soaps. The fatty raw material for lost. In some cases the exact position of the iorthe soap may be such vegetable oil as a drying mation which is producing water is not known or oil, a semi-drying oil or a non-drying oil, an anii5 is so situated that it is impossible to use the mal oil, a vegetable fat or an animal fat. Such 15 lcement or lead Wool method for plugging the soaps as sodium or potassium oleate, sodium or water oli. potassium stearate, sodium or potassium palmi- Itis an object of this invention to plug watate, can be used. ter-bearing sands encountered in oil wells with- By way of concrete example, a satisfactory fluid 2() out affecting the oil-bearing sands. which has been used comprises 10% by volume 2 Other objects would be apparent from the of sodium stearate and 90% by volume of water. specification and from the accompanying draw- Preferably the soap solution is made up in such ing, in which latter the gure is a diagrammatic a concentration that the sodium salts in the wa- Tepresentation f a preferred apparatus for carter of the earth strata may precipitate the soap l 25 rying out the invention. from solution by what is commonly known as Referring particularly to the drawing, referthe salting-out effect. The salts of calcium or ence numeral i designates the bore of a well other bases are present in the water of the earth into which extends a string of tubing 2. The strata, which bases react with the water-soluble portion of the tubing 2 protruding from the sursoaps such as sodium or potassium soaps to form 2h30 face 0f the earth iS Provided With a T-Shaped water-insoluble soaps which are precipitated in coupling 5. The T-shaped coupling 5 is provided the pores of the water-bearing sands IIJ and il. with pipes 6, 1, and 8. The tubing 2 extends sub- The solution is pumped from the reservoir I5 stantially throughout the length of the bore i into the well under suicient pressure to cause the of the well. The bore of the well pierces strata solution to pass into the Water-bearing sands ill figg-,y such as ID and Il, which are composed of waand Il where the water-insoluble soaps are preter-bearing sand which flows into the tubing 2 oipitated, lling the interstices of the sand as of the well and is delivered with oil and gas designated at 2U, resulting in the permeability of from the oil-bearing sand I3. the sand being reduced to such an extent that it The water from the water-bearing sands Ill and is impossible for water to flow from the sand into ,so Il is prevented from flowing into the bore I of the well.

' the' Well by pumping H1150r the Well aS by the Pipe By the procedure described, water-producing 8 a uid from asutable source 0f Supply l5 by formations, the location of which 1s not known means 0f a pump i5- The fluid OWS downward' are cemented off without endangering the oil- 1y through 'Phe casing 2 to the end of the asing producing formations." "The soaps are inert to 45 and than 1t flows upwardly and is delivered oil and have no effect upon'the oil-bearing forma- 45 through a line il. The fluid is maintained under tions. The soap precipitate formed 1n the water lnvgshghgg ggg Ocfaee 2 sands prevents the flow of water into the bore of ter in the porous strata I0 and Il and forces its the-'Wen When-productlon is resumed' It iS-en' Way into the porous sand permeatmg the Wa'p tirely unnecessary to know which portion of the bearing strata to the desired extent. The water producing formation carries Water and which f. in the sands Ill and Il contains soluble inorganic Portion 0f the formation Carries Oil When Carrysalts such as sodium chloride, calcium chloride, ing 011@ the Procedure described The material magnesium chloride, andthe like. The fluid, on pumped into the well is unaffected by the oil and l contact with the water in the sand, forms a, solid is flushed out from the oil-bearing formotionby 55 1. A process for plugging off salt waterpro-r ducing sands in a well producing both oil and salt Water, comprising introducing into the Well` a solution of soap and permitting the solutionv to ow into both the oil and salt waterbearing sandswhereby the soap onf'contact with the salt Water in the salt water bearing sand is salted out to plug the pores of only thes'alt 'water bearing sand forming a seal agaiustthe further entrance of Water into the well. f u

2. A process for plugging oi saltwater producing sand in a wellproducing both eiland lsalt Water, comprisingjintroducing into the well an aqueous solutionfofgsod'ium stearate and4` permitting the solutiorirt'o flow into both the oil and salt water bearing sands whereby the solution contacts the salt water in the salt water bearing sand and the sodium stearate is salted out to plug the pores. of-'only the salt water bearing sand forming avseal against the further entrance of salt. waterinto the well.

GEORGE E. CANNON. 

